求大神解答一下下

菜鸟，也没有用过asynchttp，但是用okhttp搞过传递下载进度，也许有点参考价值？

FileOutputStream out = new FileOutputStream(fileName);
InputStream in = response.body().byteStream();//从reponse中获得输入流
byte[] buffs = new byte[20460];//写入缓冲区
int count;//从输入流写入缓冲区的大小
int size = Integer.valueOf(length);//待下载文件总大小
long per;//下载百分比
long total = 0;//累计写入文件大小
long time = SystemClock.elapsedRealtime();
while ((count = in.read(buffs)) != -1) {
    out.write(buffs, 0, count);
    total += count;
    per = 100 * total / size;
    if (callback != null && (SystemClock.elapsedRealtime() - time) > 500) {
        callback.getDownloadPercentage((int) per);//回调方法，每隔500毫秒更新下载百分比一次，千万不要更新太频繁，主线程会卡住的
        Log.d("per", per + "");
        time = SystemClock.elapsedRealtime();
    }
}